Dear Peter, LF Group,
>>From G3PLX:
...Now I remove the two terminals of the coil and in it's place at the top
of the antenna I connect one end of a length of coax, with the outer braid
to the top of the antenna and the inner to the top hat. I run this coax down
the antenna. Maybe I thread it down INSIDE the antenna so that Jim doesn't
know it's there! At the bottom of the coax I connect my loading coil...
This is fine, and the same as Dick's Topload3 diagram, but with the parallel
wire stub replaced by coax - but in Figure 2b of the original article, the
connections are different. In this case, if the open wires are replaced by a
coax stub, the top hat would also connected to the coax braid as well as the
top of the mast, and the coax inner at the top of the mast wouldn't be
connected to anything! In the description above, both terminals of the top
end of the transmission line are connected to something, but in Figure 2b,
one terminal isn't connected at all.
Cheers, Jim Moritz
73 de M0BMU
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